Appendix V. 993 A is of fire-brick material, and the oil reservoir B is supplied with a compressing pump c, and a gauge D. When the cock E is opened, the fuel is fed forward under pressure till it passes through the hot coils at r, and finally- emerges through the spraying nozzle G inducing in its passage to the furnace a sufficient quantity of air to complete the combustion. The flue is fixed at H, and the rivets are put in or taken out through the door j. Pp- 339 and828. The Water-tube Boiler.—A description of the * Climax' boiler, Fig. 915, will prove interesting, not only because this boiler has shewn a high efficiency in actual practice, but because also of the totally new form of construction which it presents. It consists of a cylindrical vessel A standing vertically in the centre of the boiler, to which are attached a large number of horse-shoe-shaped tubes B c that assist circulation by reason of their lower ends c being much below their higher ends B. The fire space Q is annular in plan, and the fire is supported on a number of radiating bars. The boiler is surrounded by an outer casing u, lined with fire-brick, and there are four fire doors p p, four or more soot doors N N, and four ash doors x T. In erect- ing the boiler a brick foundation s is first laid, and after this a cast-iron plate R R, nextly the main cylinder A supporting the tubes, and lastly the casing u and the chimney. Access to the cylinder is obtained through full-sized manholes at E and D. The feed water enters at L, and may be either taken by v to the feed-water heater or economiser at H, and then by w and z to enter the cylinder at x; or it may be fed directly through Y and z to x, suitable cocks being provided to govern the direction of flow. At a is an automatic feed regulator, which is connected to a cock on the feed pipe (see p. 918). The pipe j for the outlet of steam, upon which is fixed the safety valve K, is taken from the top of the cylinder, where G is a dome space for dry steam, priming water being kept back by the deflector plate F. M is the pressure gauge. The boiler illustrated is n' 2" outside diameter, and 22' 2" in height of central cylinder, but may be carried much higher. The late Mr. Bryan Donkin made an exhaustive test of a * Climax'